Printing inks



Patented Feb. 18, 1947 PRINTING INKS Ernest D. Lee, West Englewood, N. J. assign to Interchemical Corporation, New York, N. 1., a corporation of Ohio No Drawing. Application June 25, 1946,

Serial No. 679,269

1 Claim.

This invention relates to printing inks which have the characteristic of being set by moisture, and is particularly intended to provide an inexpensive ink of this general character, characterized by good printing properties and excellent press-stability.

The setting of inks by the application of moisture as a precipitant, disclosed in the Gessler U. S. Patent No. 2,157,385, of May 9, 1939, has resulted in considerable research being undertaken to provide inks which give satisfactory printing at the higher humidities encountered in press rooms, combined with press stability, and rapid setting when exposed to moisture, whether in the liquid or vapor phase. Very few materials have been found which produce desirable inks. In general, the solvents have been restricted to the polyglycols and the polyether alcohols; the number of available resins is limited to a very few sharply defined classes, all of which are considerably more expensive than the resins commonly used in printing ink. Furthermore, all of the resins still leave something to be desired in the way of printability. As a result of these drawbacks, only a limited field of printing has been available to these moisture setting inks; they have not been able to compete in the large fields of publication and newsprinting, where low cost and good printing properties are essential elements.

In my copending application serial number 604,101, filed July 9, 1945, I disclosed that beta naphthol pitch made an excellent vehicle for inks of this general class, when dissolved in a water-soluble solvent of the class consisting of the polyglycols and the polyglycol mono-ethers.

I have now discovered that beta naphthol pitch, dissolved in propylene glycol, likewise makes an excellent vehicle for inks, which are characterized by their ability to or water-set, by their rapid drying with heat, and by their rapid setting by absorption into paper stocks.

Beta naphthol pitches are still-bottom obtained in the production of beta naphthol, when the pure product is distilled from the crude naphthol, obtained by the fusion of naphthol sulfonic acid with alkali hydroxide, followed by separa- 2 tion of the crude from the reaction mixture. Until my discovery, they have had little technical utility, being burned as waste.

Typical examples of my invention are the 01- 5 lowing: Example 1.T0ned ink Parts by weight Varnish consisting of 57% beta naphthol pitch and 43% propylene glycol 60 Water dispersible carbon black Lamp black 5 Iron blue toner (36% iron blue, 64% varnish: 47% Amberol 750 (modified phenolic resin), 53% propylene glycol) 6 15 Methyl Violet toner: methyl violet, 80%

varnish (same as'above) 2 Propylene glycol 21 This ink is a good dense black, which moisture sets, sets well by penetration into paper, and can be dried very rapidly with heat. It is stable up to about 65% relative humidity.

25 Example 2.Blaclc ink Parts Varnish of Example 1 65 Carbon black 20 Propylene glycol 15 is a rather gray ink, which dries very nicely. It is stable up to about 65% relative humidity.

Example 3 The inks will tolerate some water, particularly when a stabilizing agent such as triethanoiamine is incorporated into the ink. The typical printin; ink addends. such as wax and dispersing 1 -a8ents.=can also be incorporated.

the major binder component of whl'chls beta 10 naphthol pitch dissolved in propylene glycol; ERNEST D.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Erickson July 14, 1942 OTHER REFERENCES Grempe, Jour. Soc. Chem. Ind," 35, 463 (1916). (Copy in Science Library.)

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